The present invention relates to a process for preparing oxygen-containing organic compounds. More particularly, it is concerned with a process for preparing oxygen-containing organic compounds such as alcohols, particularly those having at least two carbon atoms from synthesis gas consisting of carbon monoxide and hydrogen with high selectivity by the use of a specific catalyst.
Various methods have been proposed to produce oxygen-containing organic compounds such as alcohols from a synthesis gas as a starting material. For example, a method using a catalyst comprising Cu/Co/Cr, Fe, V or Mn/rare earth element/ alkali metal or alkaline earth metal (Japanese Patent Application Laid-Open No. 85530/80), and a method using an alloy catalyst comprising Cu/Ti/Cr, Mo, Mn, Rh, Co, Pt or Fe/ alkali metal or alkaline earth metal (Japanese Patent Application Laid-Open No. 122045/83) are known. The former method, however, has a disadvantage in that the activity of the catalyst is not sufficiently high. This is because in preparation of the catalyst, the alkali metal or alkaline earth metal is added by the solution dipping process and, therefore, the whole catalyst becomes alkaline, leading to a reduction in the activity thereof. Also the latter method has disadvantages in that much time and labor is needed in preparation of the catalyst because it is an alloy catalyst and, as oxygen-containing organic compounds formed, methanol and ethanol are mainly produced.
As a result of extensive investigations to overcome the above problems and to develop a process for efficiently preparing alcohols by the use of a catalyst which can be easily prepared, a method has been proposed using a solid substance catalyst which is prepared by the steps of calcining a mixture of (A) a copper compound, (B) a nickel compound, and (C) a compound containing at least one metal selected from the metals belonging to Groups II, III and IV of the Periodic Table and the metals belonging to the fourth period of Groups V, VI and VII, impregnating the calcined product with (D) an alkali metal compound and/or alkaline earth metal compound, calcining the impregnated product, and then reducing it (see Japanese Patent Application Laid-Open No. 98024/84and U.S. Pat. No. 4,582,858). It has been revealed, however, that the above method permits efficient preparation of the desired oxygen-containing organic compounds and is satisfactory for practical use, but that it has a disadvantage in that nickel is dissipated during its long term use, resulting in a decrease of the catalyst activity.
Under such circumstances, further investigations have been made, and it has now been found that if nickel is used in combination with a specific component, the dissipation of nickel can be decreased and the proportion of alcohols, particularly those having at least two carbon atoms in the formed oxygen-containing compound is increased.